/********************************************************************
	created:	2010/10/20   15:52
	filename: 	sms4.cpp
	author:		cnbragon@gmail.com
	purpose:	SMS4 Implementation File
*********************************************************************/
#include "sms4.h"

NAMESPACE_BEGIN(CryptoFBC)

// const int SMS4::BLOCKSIZE = 128;
// const int SMS4::ROUNDS = 32;
// const int SMS4::DEFAULT_KEYLENGTH = 128;

const FBC_Dword SMS4::FK[ 4 ] = {
	0xA3B1BAC6,0x56AA3350,0x677D9197,0xB27022DC
};

const FBC_Dword SMS4::CK[ 32 ] = {
	0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
	0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
	0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
	0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
	0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
	0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
	0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
	0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
};

const FBC_Byte SMS4::SBox[ 256 ] = {
	0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05,
	0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99,
	0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62,
	0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6,
	0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8,
	0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35,
	0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87,
	0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e,
	0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1,
	0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3,
	0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f,
	0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51,
	0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8,
	0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0,
	0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84,
	0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48
};

FBC_Dword SMS4::T1(FBC_Dword dwA)
{
	unsigned char    a0[4]={0};
	unsigned char    b0[4]={0};
	unsigned long    dwB=0;
	unsigned long    dwC=0;
	int                i=0;

	for (i = 0; i < 4; i++)
	{
		a0[i] = (FBC_Byte)( ( dwA >> ( i << 3 ) ) & 0xff );
		b0[i]    =    SBox[ a0[i] ];
		dwB      |=   (b0[i] << ( i << 3 ) );
	}

	dwC = dwB ^ ROL(dwB, 2) ^ ROL(dwB, 10) ^ ROL(dwB, 18) ^ ROL(dwB, 24);

	return dwC;
}

FBC_Dword SMS4::T2(FBC_Dword dwA)
{
	unsigned char    a0[4] = {0};
	unsigned char    b0[4] = {0};
	unsigned long    dwB = 0;
	unsigned long    dwC = 0;
	int        i=0;

	for (i = 0; i < 4; i++)
	{
		a0[i] = (FBC_Byte)( ( dwA >> ( i << 3 ) ) & 0xff );
		b0[i]    =    SBox[ a0[i] ];
		dwB      |=   (b0[i] << ( i << 3 ) );
	}

	dwC = dwB ^ ROL(dwB, 13) ^ ROL(dwB, 23);

	return dwC;
}

void SMS4::SetKey(const char* key, FBC_Dword* rk)
{
	FBC_Dword* MK = (FBC_Dword*)key;
	FBC_Dword K[ 4 ] = { 0 };
	int i = 0;
	
	FBC_PROCESS_POINTER(key);
	FBC_PROCESS_POINTER(rk);

	for ( i = 0; i < 4; i++ )
	{
		K[i] = MK[i] ^ FK[i];
	}
	
	for ( i = 0; i < ROUNDS; i++ )
	{
		K[ i & 3 ] ^= T2( K[ ( i + 1 ) & 3 ] \
						^ K[ ( i + 2 ) & 3 ] \
						^ K[ ( i + 3 ) & 3 ] );
		rk[ i ] = K[ i & 3 ];
	}
Exit0:
	return;
}

void SMS4::ECB_Encryption(const char* plainText, FBC_Dword* rk, char* cipherText)
{
	FBC_Dword tempX[ 4 ] = { 0 };
	FBC_Dword* lpSrc = (FBC_Dword*)plainText;
	FBC_Dword* lpDst = (FBC_Dword*)cipherText;
	int i = 0;
	
	FBC_PROCESS_POINTER(plainText);
	FBC_PROCESS_POINTER(rk);
	FBC_PROCESS_POINTER(cipherText);
	
	for ( i = 0; i < 4; i++ )
	{
		tempX[ i ] = lpSrc[ i ];
	}

	for ( i = 0; i < ROUNDS; i++ )
	{
		tempX[ i & 3 ] ^= T1( tempX[ ( i + 1 ) & 3 ] \
							^ tempX[ ( i + 2 ) & 3 ] \
							^ tempX[ ( i + 3 ) & 3 ] \
							^ rk[ i ] );
	}

	for ( i = 0; i < 4; i++ )
	{
		lpDst[ i ] = tempX[ 3 - i ];
	}
Exit0:
	return;
}

void SMS4::ECB_Decryption(const char* plainText, FBC_Dword* rk, char* cipherText)
{
	FBC_Dword tempX[ 4 ] = { 0 };
	FBC_Dword* lpSrc = (FBC_Dword*)plainText;
	FBC_Dword* lpDst = (FBC_Dword*)cipherText;
	int i = 0;

	FBC_PROCESS_POINTER(plainText);
	FBC_PROCESS_POINTER(rk);
	FBC_PROCESS_POINTER(cipherText);

	for ( i = 0; i < 4; i++ )
	{
		tempX[ i ] = lpSrc[ i ];
	}

	for ( i = 0; i < ROUNDS; i++ )
	{
		tempX[ i & 3 ] ^= T1( tempX[ ( i + 1 ) & 3 ] \
							^ tempX[ ( i + 2 ) & 3 ] \
							^ tempX[ ( i + 3 ) & 3 ] \
							^ rk[ 31 - i ] );
	}

	for ( i = 0; i < 4; i++ )
	{
		lpDst[ i ] = tempX[ 3 - i ];
	}
Exit0:
	return;
}
NAMESPACE_END